1. Field of the Invention
The present invention relates to a method of effectively reading data written on a data sheet, such as a slip, and a data reading apparatus therefor and, more particularly, to a data reading apparatus which can perform optimal reading of a data sheet fed with any orientation.
2. Description of the Related Art
In a conventional data reading apparatus for reading data such as characters written on a data sheet such as a slip, the reading direction of the slip is limited to a vertical direction from the upper portion to the lower portion of the slip. Data is read, i.e., a one-line image obtained by causing a line image sensor such as a CCD scanner to photoelectrically convert light into electrical signals while the slip is being fed. The electrical signals are stored in an image buffer. For this reason, line marks 11a, 11b, 11c, and so on must be printed in advance on the slip in units of lines, as shown in FIG. 1. Line marks 11a, 11b, 11c, and so on are also called timing marks.
When a slip is fed and almost reaches a reading station in a conventional data reading apparatus, line mark 11a on the first line is detected, and feeding of the slip is interrupted. Data of the first line is then read. When the data of the first line is accurately read, the slip is fed to a position so that the next line mark 11b can be detected. In this manner, line data reading is sequentially performed on the basis of line marks 11a, 11b, 11c, and so on, and all data of one slip are completely read.
The above line marks must be printed in accordance with kinds of slips serving as objects of interest. Therefore, design flexibility of slips used for conventional data reading apparatuses is undesirably limited.
In recent years, another conventional data reading apparatus is commercially available. In addition to feeding in one direction described above (to be referred to as a normal direction hereinafter), in this apparatus, a slip can be fed in a state wherein the slip is rotated counterclockwise through 90.degree. (to be referred to as a counterclockwise 90.degree. direction hereinafter), a state wherein the slip is rotated clockwise through 90.degree. (to be referred to as a clockwise 90.degree. direction hereinafter), or an inverted direction (to be referred to as a 180.degree. direction hereinafter).
In this apparatus, however, a slip orientation must be registered in read control information (to be referred to as FC information hereinafter) prior to feeding of the slip. For example, when slips having various orientations are fed, the corresponding FC information must be set, resulting in cumbersome operations.